Abstract

Farmers all over the world had long known how to put animal and human urine and feces back on their fields to increase yields. It can therefore be seen as a small step to collect also more or less fossilized droppings from birds and bats for the same purpose. Off the west coast of South America, birds feeding on anchovetas and other small fishes in the rich upwelling zones nest on a number of small islands, where guano deposits have accumulated over centuries or millennia and reached thicknesses as great as 50 m, as on the islands of Chincha. The first to utilize those and apply guano on their fields were Andean Indians. In small boats and further on, on the back of llamas, they transported the fertilizer from some of the nearby islands up to their terraced farmland in the mountains. The Incas had an advanced system for distributing the fertilizer to villages in relationship to the taxes they paid and the labor days they provided to the central system. To take guano allocated to another village was a serious crime with stiff penalties. Disturbing the bird colonies during the nesting season was also unlawful.